It's 2013 and Peter Williams, a Professor of History at New York University, is obsessed with an old war story about the USS Lionfish, a US Navy submarine that was mysteriously and suddenly chained, welded shut, sealed and locked to a pier in 1943. Peter, after becoming an embarrassment to the Navy War Department, is forced to resign his position at Boston University due to his drinking and his single minded obsession with the submarine story. That evening, he receives a mysterious visit from a man from the Department of the Navy. After years and years of trying, Peter is allowed to visit the submarine. Assembling his team of researchers, including is ex-wife, Peter plans to finally perform research on board, and his team head to the USS Lionfish. The first people to be allowed on the Sub for over 70 years. But, once on board, they become trapped by the boat itself and things only get worse for the team as the boat reveals it's dark secrets…
